I bought this pack for hauling very dense loads (geologic samples) on day trips, and it has performed admirably. The quality materials and burly suspension make this pack a bit heavier than many other in its size class, so if you're looking for a mid-sized pack for ultralight backpacking, I'd recommend looking elsewhere. Osprey makes a backpacking version of this pack (the Stratos line) without the side compression system, and it weighs like half as much.

I find the external side mesh pockets to be too snug to conveniently use 1L Nalgenes, but other than that I have no complaints. The harness system is solid and easily adjustable. The hipbelt, though not as fancy as a bigger backpack, is comfortable and durable. The side-wall compression system is awesome, and I recommend it to anyone who typically packs oddly sized loads that wouldn't otherwise ride well.

The huge U-shaped zipper is a real plus, it opens the pack up top to bottom with a single pull. The hydration pocket fits 2L but not 3L hydration bags in a removable pack that uses the pack's regular shoulder harness system, which is nice, but it's kind of difficult to remove or put back in, involving multiple buckles and a large interior velcro sheet.

I mostly use this pack for single overnight trips or gear-intensive daytrips like rock climbing. It carries better than most mid-sized packs when heavily weighed down, but you pay for that comfort with an extra two pounds of pack weight.